1. Field of the Invention.
The present invention relates generally to non-creped webs for towel and tissue and, more particularly to methods for making non-creped webs with improved uniformity in the base sheet.
2. Brief Description of the Prior Art,
U.S. Pat. No. 3,301,746 to Sanford, et. al. teaches a process for forming absorbent paper by imprinting a fabric knuckle pattern thereon. Sanford, et. al. teaches a process whereby the papermaking furnish is delivered to a forming wire. The uncompacted paper web is vacuum dewatered and transferred to the imprinting fabric. The imprinting fabric carries the web through a hot air dryer to thermally pre-dry the web from about 30% to 80% dry. The pre-dried web still supported on the imprinting fabric is pressed against and transferred to the surface of the Yankee dryer. The web is then creped from the Yankee dryer surface. An alternative embodiment is also taught by Sanford et. al. wherein the papermaking furnish is distributed directly on an imprinting fabric. The web is once again vacuum dewatered, thermally predried, and then pressed against and transferred to the surface of the Yankee dryer, while supported on the imprinting fabric. The web is then pulled from the surface of the Yankee Dryer.
U.S. Pat. No. 4,102,737 to Morton teaches a twin wire forming operation wherein the foraminous drying/imprinting fabric used to thermally pre-dry a moist web is extended to the twin wire formation zone. As in Sanford, the web is ultimately transferred to the surface of the Yankee drum being pressed thereon using the imprinting fabric and the web is then creped from the drum. Prior to the transfer of the web to the surface of the Yankee dryer, the web is thermally pre-dried to a fiber consistency of at least about 30%, and most preferably, to a fiber consistency between about 30% and about 98%.
U.S. Pat. No. 4,440,597 to Wells, et. al. teaches a method for shortening a wet laid embryonic web through the use of a differential velocity transfer from the carrier fabric to a transfer or imprinting fabric (negative draw). The web is ultimately transferred to a Yankee and creped therefrom. Prior to transfer to the Yankee dryer surface, the web is pre-dried.
U.S. Pat. No. 5,048,589 to Cook, et. al. teaches a non creped and/or wiper towel is made by forming a furnish which includes a chemical debonder, depositing that furnish on a forming wire, moving the web on the forming wire to a through dryer to non-compressibly dry the web, and then removing the dried web from the foraminous wire without creping. Cook et. al. further suggests that the transfer from the forming wire to the through dryer can be made with a negative draw. By negative draw, it is meant that the forming wire is travelling faster than the through drier belt.